Method: Vary heat flux. Vary temperature and relative
humidity of air.
Process: Net vapor rate zero. Evaporative cooler.
Advantages: Exchanger film temperatures at maximum.
Disadvantages: Local pump required. Response may be slow
due to system liquid inventory.
Application: Condenser always runs at maximum temperature
consistent with duty removal. This can be useful to prevent localized
solidification in some processes. Often used in climates that
may have very cold operating days to prevent plugging from solids.
Variants:
Configuration notes: The evaporative condenser essentially
includes the cooling tower in the condenser. It may include a
dedicated bypass fan to improve control. Process industries have
been moving away from the evaporative condenser towards cooling
tower provided water over the last 20 to 30 years.
Operation: Water humidification into the air controls the
duty removal. Controlling the net air rate to the system varies
the amount of water that can vaporize to remove heat (exit air
at 100 percent relative humidity). Unit LMTD decreases with lower
air rates.
Warnings:
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